1. Field of the Invention
The invention relates to a vehicle lighting device that uses a light emitting element, such as a light emitting diode, as a light source.
2. Description of Related Art
Japanese Unexamined Patent Publication No. 2001-294079 is an example of several recent proposals to use light emitting diodes (LEDs) as light sources for some vehicle lighting devices in place of electric bulbs, such as base bulbs or wedge base bulbs. However, LEDs require lighting circuits with resistors and diodes for luminance control and protection. Accordingly, a printed circuit board has been required for lighting circuits of LEDs.
The resistors and diodes have been soldered to the circuit pattern of the lighting circuits on the printed circuit board of the prior art vehicle lighting device and this operation is cumbersome. The luminance of the LED can be adjusted, for example, by changing the capacity of the resistor (resistance value). However, changing the soldered resistors is not easy. Thus, the luminance generally is not adjusted. Further, there are several other problems including the tendency of the printed circuit board to take up a large space. Thus, there is earnest demand for further improvements.
The present invention was developed in view of the above problems and an object is to decrease production costs for such vehicle lighting devices.